As Star exclusively reported, the singer and Entourage star were “very flirty” at the Republic Records holiday party on Dec. 12. When the story was brought to the 20-year-old’s attention though, she tweeted, “who the hell is that?” and added, “Lmao I’m sure he’s lovely.”

A fan then took to the social media site with evidence that Ariana isn’t telling the whole truth. “ehh she knows who he is …,” she wrote, with a photo of a woman sandwiched by both stars.

Despite the duo’s 17-year age difference, an insider tells Star that they spent the entire night of the holiday party playfully touching each other before disappearing together. Their flirty night came just shortly after Ariana split from The Wanted’s Nathan Sykes.